Technical Field
The present disclosure relates to connector combinations. More particularly, the present disclosure relates to connector combinations including a receptacle connector capable of mating with plug connectors with mating heads of different lead-in lengths.
Description of Related Art
In general, bus connectors of a computer are required to be expanded as the communication interface for information transmission between the internal elements in the system. PCI Express (PCIe) bus connectors are the most common expanding bus connector in computers. Since a PCIe bus connector has a relatively higher maximum throughput and a minimum input/output pin counts (I/O pin count), PCIe bus connectors have become the main stream of the bus connectors of computer systems. In recent years, the Peripheral Component Interconnect Special Interest Group (PCI-SIG) has launched a cable system following the PCIe specifications, known as the PCIe Oculink cables. The PCIe Oculink cables can be regarded as an extension of the PCIe bus connectors. The PCIe Oculink cables can be connected to different storage devices inside a computer, and can be utilized outside a computer to connect various devices supporting the PCIe specifications to the computer.
Please refer to FIG. 1. FIG. 1 is a perspective view of a traditional PCI Express (PCIe) Oculink connector assembly. As shown in FIG. 1, a PCIe Oculink board end double layers connector combination 100 includes a receptacle connector 118 and two plug connectors 112, 114. Please also refer to FIG. 2. FIG. 2 is an exploded view of the plug connector of FIG. 1. As shown in FIGS. 1-2, the plug connectors of the traditional PCIe Oculink connector assembly include two plug connectors 112, 114, an external steel case 110 and a spacer 212. The spacer 212 is utilized as the back plate supporting the plug connectors 112, 114, so as to strengthen the mechanical stability of the plug connectors 112, 114. The external steel case 110 covers outside the plug connectors 112, 114, configured to fix and plug together the plug connectors 112, 114. The plug connectors 112, 114 are respectively connected to the cables 124, 126. The plug connectors 112, 114 respectively include a plug body 112c, 114c, and an upper metal cover 112a, 114a, and a lower metal cover 112b, 114b, respectively configured to cover the plug bodies 112c, 114c. The plug bodies 112c, 114c respectively have an insulating housing 211, 213, and a plurality of metal terminals 214, 215, in which the metal terminals 214, 215 are respectively interposed inside the insulating housings 211 and 213. The metal terminals 214, 215 are divided into the upper and the lower rows respectively disposed on the upper surface and the lower surface inside the insulating housing 211, 213, in which each of the rows has 21 metal terminals. The plug bodies 112c, 114c further include a steel case 216, 217, configured to accommodate the insulating housings 211, 213. The portion of the steel cases 216, 217 protruding from the upper metal covers 112a, 114a and the lower metal covers 112b, 114b form a mating head 216a, 217a having an inner hollow space to mate with the plug connector 118. Please be noted that, in this specification, similar elements are presented by the same marking number.
Please also refer to FIG. 3. FIG. 3 is an exploded view of the receptacle connector of FIG. 1. As shown in FIGS. 1 and 3, a traditional PCIe Oculink receptacle connector 118 includes an external metal case 118a and a connector body 118b. The external metal case 118a is configured to cover the connector body 118b. The connector body 118b includes a plastic base 300 and a plurality of metal terminals 306, in which the plastic base 300 includes an upper tongue plate 302 protruding forwards from an upper region of the front portion of the plastic base 300, and a lower tongue plate 304 protruding forwards from a lower region of the front portion of the plastic base 300. The metal terminals 306 are respectively interposed into the grooves on the upper surface and the lower surface of the tongue plates 302, 304, such that two receiving grooves are formed at the front portion of the receptacle connector 118. The mating head 216a is configured to insert into the receiving groove where the tongue plate 302 is located, and the mating head 217a is configured to insert into the receiving groove where the tongue plate 304 is located. When the receptacle connector 118 is mated with the plug connectors 112, 114, through the snapping of the of the groove 307 on a side of the tongue plate 302 and a corresponding groove (not shown) on a side of the insulating housing 211, 213, the receptacle connector 118 and the plug connectors 112, 114 are fixed, such that the mating heads 216a, 217a abut against the plastic base 300, as shown in FIGS. 1 and 3.
In general, the lead-in lengths of the mating heads 216a, 217a of the standard PCIe Oculink plug connectors 112, 114 are subject to strict specifications. Please refer to FIG. 4A. FIG. 4A is a perspective view of a standard PCIe Oculink plug connector. As shown in FIG. 4A, the lead-in lengths d1 of the mating heads 216a, 217a of the standard PCIe Oculink plug connectors 112, 114 are 5.95 mm. However, when the PCIe Oculink plug connector is to be applied to the outside of a computer, since the lead-in lengths of the mating heads 216a, 217a are often too shallow, the plug connectors 112, 114 are easily collided or flipped and the problem of supporting failure is produced. Please refer to FIG. 4B. FIG. 4B is a perspective view of an elongated PCIe Oculink plug connector. If the lead-in lengths of the mating heads 216a, 217a or the metal cases 216, 217 are increased, as shown in FIG. 4B, the lead-in lengths of the mating heads 216a′, 217a′ of the PCIe Oculink plug connectors 112′, 114′ are d2 (for example, 8.45 m), the tolerability of the plug connectors 112′, 114 against stress can be strengthened, such that the PCIe Oculink connectors are suitable to be used outside a computer. However, due to the extension of the lead-in lengths of the mating heads 216′, 217′ of the elongated PCIe Oculink plug connectors 112′, 114′, the elongated PCIe Oculink plug connectors 112′, 114′ cannot be successfully mated with the receptacle connector 118. Thus, such prior art requires improvement.